The objective of this project is to identify biological factors influencing reproductive function and embryogenesis in felid species. Emphasis is placed on gamete interaction and embryo maturation in vitro and in vivo. Findings are relevant to (1) fundamental studies of fertilization mechanisms, gametogenesis, and early embryogenesis; (2) the propagation of genetically valuable laboratory animals and endangered species; and (3) developmental studies which eventually will allow delivering molecularly cloned genes into early-staged pre-implantation embryos. Areas of effort primarily focus on (1) in vitro fertilization and embryo development in vitro and in vivo; (2) artificial insemination via laparoscopic deposition of spermatozoa; and (3) oocyte rescue, maturation in vitro and the development of gene delivery techniques into embryos which will allow studying the mechanisms associated with transformation and inborn errors in early development. Current emphasis is applied to the gametes and embryos of the domestic cat with comparative studies conducted in a variety of nondomesticated Felidae species. To date, progress has allowed (1) comparison of factors which influence in vitro fertilization and embryo development in vitro in domestic cats and nondomestic felids (i.e., gas atmosphere, medium, protein sources, temperature); (2) development of suitable embryo recipients after fertilization and embryo production in ; (3) initiation of in vitro fertilization studies involving felid species producing large proportions of abnormal sperm and which reproduce poorly in captivity; (4) development of assays measuring permeation of domestic cat oocytes and embryos to cryoprotectants useful for developing embryo freezing protocols; and (5) continued success in the development of an efficient transabdominal artificial insemination approach in the domestic cat which has lead to comparative studies in nondomestic felids including production of domestic cat x leopard cat hybrids produced to develop a high resolution genetic linkage map of the domestic cat in order to further understand the genetic loci involved in neoplastic transformation as well as other disease states.